title: About the role of phase matching between a coated microsphere and a tapered fiber: experimental study.
abstract: Coatings of spherical optical microresonators are widely employed for different applications. Here the effect of the thickness of a homogeneous coating layer on the coupling of light from a tapered fiber to a coated microsphere has been studied. Spherical silica microresonators were coated using a 70SiO(2)- 30HfO(2) glass doped with 0.3 mol% Er(3+) ions. The coupling of a 1480 nm pump laser inside the sphere has been assessed using a tapered optical fiber and observing the 1530-1580 nm Er(3+) emission outcoupled to the same tapered fiber. The measurements were done for different coating thicknesses and compared with theoretical calculations to understand the relationship of the detected signal with the whispering gallery mode electric field profiles.
authors.forename: Davor
authors.initials: D
authors.lastname: Ristić
authors.forename: Alphonse
authors.initials: A
authors.lastname: Rasoloniaina
authors.forename: Andrea
authors.initials: A
authors.lastname: Chiappini
authors.forename: Patrice
authors.initials: P
authors.lastname: Féron
authors.forename: Stefano
authors.initials: S
authors.lastname: Pelli
authors.forename: Gualtiero Nunzi
authors.initials: GN
authors.lastname: Conti
authors.forename: Mile
authors.initials: M
authors.lastname: Ivanda
authors.forename: Giancarlo C
authors.initials: GC
authors.lastname: Righini
authors.forename: Gilles
authors.initials: G
authors.lastname: Cibiel
authors.forename: Maurizio
authors.initials: M
authors.lastname: Ferrari